At 02:41 PM 10/4/1998 +1300, you wrote:
>I would like to build a a 5V d.c. power supply for a PIC derived from
>the mains supply of 230V A.C. with out using a transformer.
>
>Currently my only idea is to use a couple of 5W ceramic resistors in
>series across the mains supply as a voltage divider and use this to
>supply a bridge rectifier / three terminal regulator circuit.
>
>Is there a better or more efficient way of obtaining 5V d.c. with a
>small compact circuit?
>
>
>Seth Fischer
>

Hi Seth,

Harris has some integrated circuits which can take 50-280V A.C. and will
convert it to 5 V, without the use of a transformer.  The current is
relatively low (30 to 50 mA), however, but it should be able to power a
PIC.  Check out the HIP5600 and HV-2405E from Harris, www.semi.harris.com.
 Also check out the article "Transformerless Power Conversion", by Jeff
Bachiochi, in the Aug 98 (Issue #97) of Circuit Cellar Ink, pp 78-80.

Regards,
Gary Pepper

Ottawa, Ontario, Canada
e-mail: gpepper@capitalnet.com